Within the scope of the manufacture of equipment for cleaning and/or for waste collection and treatment, it is known to use suction/compression assemblies configured to generate the vacuum in a collection system, which may be for example a tank mounted on a vehicle, and/or to compress air into the system itself. More precisely, the expression “suction/compression assembly” means the combination formed by an operating machine and by the components required to connect the same to any system with the purpose of aspirating or compressing gas from/into the tank while preventing leakage/loss of the gas itself.
The operating machines normally used in such assemblies are of the volumetric type, that is, configured to transfer a mass of gas from an intake section to an exhaust section of a chamber. To this end, in most cases, lobe rotors are positioned within the chamber through which the transfer of the gas mass between the indicated sections is carried out.
It is also known that a suction/compression assembly may be used to carry out work under pressure or vacuum working. In the first case, the operating machine compresses the air from the intake section, at substantially atmospheric pressure, to the exhaust section with a variation normally of the order of 1 bar. Also in the case of vacuum working, the machine compresses the air from the intake section to the exhaust section, but the latter is at atmospheric pressure. The maximum depression usually reaches 50 mbar. In order to allow varying the operation of the machine, the intake assembly comprises a four-way valve which is adjusted in at least two operative positions. In the first operative position, corresponding to vacuum working, the intake section of the chamber is made communicating with the system and the exhaust section is made communicating with the external environment. In the second position, corresponding to work under pressure, the intake section is made communicating with the external environment and the exhaust section with the system.
During the normal operation of a suction/compression assembly, the gas at the exhaust section has a higher temperature than the intake section. Irreversibility and volumetric losses increase the real value of the exhaust temperature compared to an ideal value calculated by assuming that the passage of the gas in the chamber takes place according to a reversible adiabatic transformation. In order to limit/lower the compression end temperature, gas is introduced inside the chamber to prevent the compression from being carried out by the exhaust gas at the exhaust temperatures, but by the injection gas substantially at ambient pressure and temperature (lower than that of exhaust).
In any case, it has been seen that in currently known suction/compression assemblies, the technical solutions adopted for the direct injection of gas into the chamber are not satisfactory, especially in terms of encumbrance. Mutually independent pipes are normally used for gas injection, which have complicated shapes and determined in part by the structure of the components of the operating machine. In this regard, a particularly critical component of the operating machine is represented by the elements which allow the connection of the machine to the equipment for which the machine is intended. It has been seen that the number, the arrangement and the configuration of the connecting elements greatly affects the configuration, the position, the number of injection pipes that can be installed and, ultimately, the cooling efficiency.
Moreover, the definition of the injection pipes must also take account of the available space on the equipment for which suction/compression assembly is intended. In this sense, the injection pipes currently used are little versatile and actually usable for only one installation configuration of the assembly.
In view of the above, the main task of the present invention is to provide an suction/compression assembly which allows overcoming the limits of the prior art described above. Within this task, a first object of the present invention is to provide a particularly compact suction/compression assembly. Last but not least, an object of the present invention is to provide a suction/compression assembly that is compact, reliable and easy to be implemented in a cost-effective manner.